Hello~You might have some vertebrae misalignment in your lower back, this can cause spasms. I would see a chiropractor. He/she will take an x-ray of your lower back, if they see an area that needs attention, they will work on it, after a few treatments, you should start to feel better and the twitching should stop. I would also take a good multi-mineral supplement with emphasize on Calcium and Magnesium, these two minerals, when deficient, can also cause the twitching.